In the past two decades, Florida and five other states have repealed or relaxed laws that required every motorcyclist to wear a helmet. Charting fatal motorcycle accidents in each of those states shows a clear trend: As soon as the law changes, the number of fatalities rises. In fact, Florida leads the nation.
More state legislatures are considering similar changes this year, with measures that would replace universal helmet laws with requirements only for categories of specific riders - like those younger than 21, or those who do not have certain training or insurance.
Safety experts say they are particularly concerned that motorcycle deaths are increasing at the same time that auto vehicle deaths are decreasing. Roads are getting safer for drivers and their passengers, but more dangerous for motorcyclists. At the same time, motorcycle advocacy groups are pressing for changes in helmet laws.
When Florida relaxed its law in July 2000, it required helmets only for riders younger than 21 and those with limited medical insurance policies. Safety experts watched closely to see what would happen in the state, which has a large population and a strong motorcycle culture.
Fatalities among motorcyclists who did not wear helmets rose more than sevenfold, to 164 in the year after the new law from 23 in the year before. Motorcycle registrations also increased overall, dipping in 2009 as the economy faltered. Fatalities involving helmet wearers rose with ridership, but many more of those who died were not wearing helmets.
Andreas Muller, a professor of health policy at the University of Arkansas who studied the effect of the law in Florida, published research in the American Journal of Public Health confirming that the law resulted in many more deaths even after adjusting for increases in registrations.
"Helmet use dropped significantly in Florida, even for the young people the law tried to protect, because it's unenforceable," Muller said. "How can a policeman know how old a rider is as he flies by on a bike? It's a legislative failure."
Despite such results, Pennsylvania replaced its universal helmet law in 2003, and Michigan in 2012. Of the 19 states that still have universal helmet laws, eight are considering legislation to weaken those laws this year, according to the National Conference of State Legislatures.
Those eight states are being pressured by state motorcycle advocacy groups and the Motorcycle Riders Foundation, a national organization that says part of its legislative agenda is "to fiercely oppose any mandatory helmet or apparel standards."
"We are 100 percent anti-helmet laws, but we are 100 percent pro-helmet," said Jeff Hennie, the foundation's vice president for government relations. "We believe that the government should not tell you to wear a helmet."
© 2014 New York Times